1. Field of the Invention
The present invention relates to a screen on which an optical image is projected from a high brightness CRT, a liquid crystal projector, or a projector that uses a micromirror device. The present invention also relates to an image projector system that uses the screen.
2. Description of the Related Art
Image projector systems such as projector devices that display images by projecting optical images utilizing a high brightness CRT, a liquid crystal projector, a projector using a micromirror device, or the like can simply and easily display a high definition image on a large screen. Consequently, image projector systems are widely used as information communication tools among a plurality of users. The light utilization efficiency of an image projector system may be increased by using a structure in which a white color material or a reflective film is used to cover a surface of the screen, and the visibility of the screen with respect to a plurality of viewers may be increased by distributing beads in a surface of the screen, thus diffusing light. Alternatively, as disclosed in JP 2002-169224 A, it is known to perform image display with good efficiency to a plurality of viewers by providing a directionally reflective structure such as a lenticular lens to a screen surface.
Problems as described below exist, however, with conventional techniques. Although a wide field of view can be achieved with a screen made by using diffusion materials such as beads, the screen becomes dark due to low gain. Further, although a bright screen having a high gain can be obtained by using lenticular lenses due to high directionality, the field of view of the screen becomes narrow. Furthermore, screens used in projectors that employ lenticular lenses are manufactured by forming transparent resins such as acrylic resins, and the manufacturing process thus cannot be made low cost. In addition, image quality degradation becomes large for a medium or small size screen on the order of 8 to 20 inches when viewing an image at a short distance from the screen.